Internal combustion engines having external ignition, especially internal combustion engines having direct injection, are operated in various operating modes. These operating modes differ for instance in the mixture formation and thus the application strategy and the software functions for the injection system, the air system and/or the ignition system. The application data for the functions that are specific to the operating mode are stored in different setpoint value characteristics map structures. The switch to a particular operating mode depends on the engine operating point, the ambient conditions and/or the instantaneous state of the drive train and/or the vehicle. To coordinate the switch in operating modes in externally ignited internal combustion engines, the operating mode having the most optimal fuel consumption is selected as a function of the aforementioned variables.
Modern internal combustion engines having direct injection, especially diesel engines, use exhaust-gas aftertreatment systems. Furthermore, it may be provided to introduce novel combustion methods to lower the emissions. Different application strategies and software functions specific to the operating mode, which are coordinated and switched as a function of the engine operating point, the ambient conditions and/or the instantaneous state of the drive train and the vehicle, are utilized in this context.
In externally ignited internal combustion engines the switchover and the selection of the operating mode are essentially selected as a function of consumption, i.e., the operating mode providing the lowest consumption will be chosen. This approach cannot be transferred to an internal combustion engine having direct fuel injection since different requirements regarding the selection of the operating mode exist there. In this case, the operating modes are selected on the basis of the requirements of individual subsystems. For instance, it may be provided that the internal combustion engine be equipped with a particle filter. A regeneration of this particle filter will be required in the presence of certain operating states, so that a switchover to the regeneration of the particle filter operating mode must then be made. Compared to an operating mode having low fuel consumption, this operating mode has a clearly higher priority under certain circumstances.
According to the present invention, in a device and a method for controlling a combustion engine, the air quantity supplied to the internal combustion engine is able to be controlled by a first actuator, and/or the fuel quantity supplied to the internal combustion engine is able to be controlled by a second actuator in at least two operating modes, the operating mode being processed as a function of its assigned priority and this priority being predefinable.
Due to the fact that the operating mode is processed as a function of its priority, the priority being predefined, it is possible to prioritize the requests of the subsystems in a variable manner and to process them at a variable priority. In an especially advantageous development, it is provided that the operating-mode coordinator not only process the request of the operating mode of the subsystem, but in addition also priority information that is predefined by the subsystem in an especially advantageous exemplary embodiment. The processing sequence of the requests is not stipulated, but is variable on the basis of the additional priority information. Before processing of the requests takes place within the operating-mode coordinator, the requests are sorted according to their priority.
It is especially advantageous that the operating mode and/or the priority of the operating mode are/is predefined as a function of an engine operating point, ambient conditions and/or a state of an exhaust-gas aftertreatment system.
The operating modes are preferably requested by a subsystem. The corresponding subsystem also specifies the priority at which the request is to be processed.